Every year, the same pattern. The week before Black Friday, three clients call us with the same realisation: the store has not been load-tested, the inventory sync was last touched in March, and nobody is sure what happens when the payment provider rate-limits. Here is the checklist we run with merchants who want to sleep through the weekend.
Performance: the obvious one, mostly handled
If you are on Shopify, the platform itself will not fall over. Your bottleneck will be apps - especially anything that injects scripts on the storefront, calls external services in a webhook, or runs synchronous logic in checkout. We turn off non-essential apps for the weekend, defer everything that can be deferred, and pre-warm caches on key collection pages.
On WooCommerce, the story is different. The host matters, the cache matters, and so does the database. We run a real load test against a staging copy a month out, fix what breaks, and move to a managed host with autoscaling if the current one cannot handle a 5x traffic spike.
Inventory: where the real money leaks
The most expensive Black Friday failure is not downtime. It is overselling. If the store and the warehouse drift even slightly, you spend the next two weeks emailing customers to say their order is cancelled - and they remember it for a long time.
We test the inventory sync end-to-end the week before. A webhook drop, a 500 error, a rate limit - all of these can cause silent drift. We add a reconciliation job that runs every ten minutes during the peak and pages the team if numbers diverge by more than a threshold.
Payments and tax: have a fallback
Stripe, Adyen, and Barion all have rate limits. So does your tax service if you use one. We confirm the limits in writing, ask the provider whether they can be raised for the weekend, and add a fallback - a second processor on a small share of traffic, or at least a graceful “try again in a moment” message that does not lose the cart.
Integrations: the silent failure modes
Order confirmations through your ESP. Stock updates to your ERP. Shipping label generation. Each of these is a webhook, and each webhook can quietly fail. We add monitoring on the queue depth and the success rate of every key integration, with alerts that go to a real human’s phone, not a Slack channel that is muted on Saturday morning.
A war room, even a small one
For peak hours we set up a shared channel and a one-page runbook - who restarts the queue, who calls the host, who reaches the payment provider. Most years, nothing happens and the runbook is unused. The years it is needed, it pays for the entire engagement in fifteen minutes.
How we help
We run pre-Black Friday readiness audits for Shopify and WooCommerce stores - typically four to six weeks out, ideally earlier - and we are on standby through the weekend itself for clients who want a hand on the wheel. If you are heading into the peak with a store you have not stress-tested, that is the conversation worth having now, not on the 27th.
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